CZ304588B6 - Rotary piston machine for compressible media - Google Patents

Abstract

The present invention relates to a rotary piston machine for compressible media, comprising rotary pistons that are sealed into a common housing and that rotate with one another in a forced manner. Said rotary pistons have a plurality of disk-type sections, which engage in pairs with one another and whose thickness and/or diameter reduces towards the pressure side. Each disc has an outer surface (M1, m1) and an inner surface (K1', k1'), respectively connected by an intermediate surface (z1'), the sector angle of the outer surface and the inner surface of each disk being unequal. The disks have different transverse profile contours, which are periodically repeated along the piston axis and each disk is offset at an angle to the two neighboring disks of the same piston in such a way that said three disks have a common surface section and form a chamber.

Description

The invention relates to a rotary piston machine for compressible media having at least two rotary pistons sealed in a common housing and rotatable in a controlled manner relative to each other, wherein the rotary pistons have a plurality of disk sections which engage with each other in pairs whose thickness decreases towards the pressure Each disc has at least one surface area and one core surface formed by the control curves running along the arcs of circles centered on the axis of the respective rotary piston, and respectively interconnected by an intermediate surface.

BACKGROUND OF THE INVENTION

Rotary pistons for vacuum pumps or positive displacement pumps for gases are usually manufactured as pairs of screw spindles. For the purpose of extrusion or compression, these screw spindles have a variable pitch. Screw compressors for gases with two screws which engage with each other and whose pitch decreases constantly towards the pressure side are known.

Although such compressors are capable of achieving high compression ratios, the manufacture of pairs of screw spindles with different pitch axes is very difficult, especially because the screws must engage with each other as much as possible without any play in order to achieve minimum pressure losses. This means that the production of a screw compressor of this type is very expensive.

On the other hand, so-called Roots blowers are known, provided with two disk-shaped rotary pistons which engage with each other. The air passage occurs diagonally opposite the rotational axis of the rotary pistons, so that these compressors are suitable for large amounts of air, but only for low compression ratios.

In order to achieve high compression ratios it is necessary to use several compressor units of this type, connected in series or arranged to form a multi-stage Roots blower.

In order to avoid the difficult manufacture of variable pitch pitch spindles, it has already been proposed to develop rotary pistons as rotary pistons with decreasing shoulder.

DE 29 34 065 discloses such rotary pistons with reduced stocking in a rotary piston machine of the type already mentioned at the beginning of this text.

In this machine, the spindles are provided with pseudo-threaded grooves formed by stepped recesses, provided with circumferences at right angles to the spindle axis and one after the other in the screw line. In these grooves, in a plane defined by the two spindle axes, a correspondingly formed thread-type ridge at the opposite spindle engages and defines a groove volume with each thread, so that as the spindles roll one after another, the ridge moves the groove volumes with compressible medium so that the groove volumes vary and the desired pressure difference between the inlet and outlet is thus achieved.

The spindles have a semicircular contour in their cross-section with a cut-out defined by the core region and with two shoulders forming intermediate regions. The sector angles of the outer surfaces and inner core regions have the same size, in particular 180 °.

- 1 GB 304588 B6

A disadvantage of these rotary piston machines is the large number of stepped circuits necessary to form a groove in the form of a pseudo-thread, the manufacture of which requires a large number of machining operations.

A further disadvantage lies in the high degree of precision of the machining of the abutment surfaces, which is required in order to minimize pressure losses between the stages.

A simplified construction of a shrinking rotary piston is described in DE29 44 71. In this publication, a laminated construction of rotary pistons is proposed, each rotor comprising a plurality of individual disks of identical front profile, in particular with surfaces and core surfaces, each it has a 180 ° section angle but with varying thicknesses or diameters.

The absence of sealing effect between the rotary pistons of this design, which causes gas backflow and low compression ratio, should be compensated for by high operating speed, which in turn brings thermal and mechanical problems as well as high noise levels.

Previously published patent AT 261 792 also discloses a rotary piston machine of this type, in which the gradually tapering rotary pistons comprise individual discs of identical cross-section. Each disk has two outer surfaces opposed to each other and two inner core faces opposed to each other, the section angles of which are all equal and are 90 °.

With this disc shape and with this rotor offset arrangement, the gap width between opposing discs must be kept as small as possible. The surfaces and core surfaces are therefore connected by intermediate surfaces formed as expanded epicycloids to provide a sealing effect between the disks. As a result, both their profile and the external synchronization device of the machine must be machined very precisely, which is expensive.

Although the aforementioned patent publication AT 261 792 provides a reduction of the thermal load at the edge ends by a rounded shape, it cannot remove the backflow of the gas.

SUMMARY OF THE INVENTION

The present invention relates to the manufacture of a rotary piston machine with a high compression ratio, in particular a vacuum pump which provides a better end vacuum than a rotary vane pump and which is approximately similar to multi-stage Roots blowers.

The manufacture of such a machine can be much less expensive than multistage pumps, and also much less expensive than screw pumps. In addition, the internal compression of the compressible medium or gas is performed in order to achieve a reduction in energy consumption as well as a reduction in the operating temperature. Finally, noise levels during operation should be as low as possible.

Accordingly, in accordance with the present invention, there is provided a rotary piston machine for compressible media, with at least two rotary pistons sealed in a common housing and rotatable relative to each other in a controlled manner, wherein the two rotary pistons have a plurality of disk sections that engage with each other in pairs whose thickness and / or diameter decrease in the direction of the pressure side, each disc having at least one surface area and one core surface formed by control curves extending along the arcs of the centers on the axis of the respective rotary piston, and respectively interconnected by an intermediate flat.

-2GB 304588 B6

The section angle of the surface area and the core surface of the respective disc are not identical, the discs having different transverse profile contours, repeating periodically along the piston axis, each disc being offset at an angle relative to two adjacent discs of the same piston in such a way a control curve through one section of their core surfaces and form a chamber.

Preferably, the two adjacent disks of a disk having a surface area whose section angle is greater than the section angle of the core surface have surface areas whose section angles are smaller than the section angles of the core surfaces.

Advantageously, the intermediate surfaces of the disc form a continuous intermediate surface with a common control curve with the intermediate surface of the adjacent disc.

The two rotary pistons are preferably mounted off-axis and parallel axes, said discs having outer surfaces and inner core surfaces which are formed by the control curves of the respective one outer cylinder and one core cylinder, the thickness of the disk-shaped sections decreasing towards the pressure side.

The synchronization device is preferably arranged to provide the opposite direction of rotation on the two rotary pistons.

The diameters of the outer surfaces and the core surfaces of the two rotary pistons are preferably identical.

The section angle of the outer surface area of each second rotary piston disk is preferably less than 90 °, in particular less than 60 °.

The thickness of the disks in the direction towards the pressure side preferably decreases every two disks by a constant factor.

The rotary pistons preferably have different outer diameters, wherein the thickness of the main rotor sections having an outer surface area with a small section angle is correspondingly greater than the thickness of the main rotor sections having a surface area with a large section angle.

The diameter of the core surface of the main rotor is preferably equal to the diameter of the outer surface of the secondary rotor.

Preferably, each rotor of the main rotor has two opposing core surfaces and two outer opposing surfaces, the speed of rotation of the secondary rotor being twice that of the main rotor,

The synchronization device is preferably arranged to provide the same direction of rotation of the rotary pistons, the rotary pistons having different outer diameters, and the thickness of the main rotor sections having an outer surface area with a small section angle is correspondingly greater than the thickness of the main rotor sections. surfaces with a large section angle.

The sequence of periodically repeating transverse profile contours includes discs consisting only of a core cylinder and / or locking discs.

The rotary piston machine according to the invention preferably comprises rotary pistons mounted on an inner axis, in particular an outer rotor, an inner rotor, and a G-shaped rotor, the outer rotor and the inner rotor having a plurality of disk-like sections engaging each other in pairs. the thickness and / or diameter decreases in the direction of the pressure side, each disk of the outer and inner rotor having at least one surface area and one core surface formed by control curves running along the arcs of the circles centered on the axis of the respective

The rotor angles of the surface and the core surface of the respective disc are not identical, wherein the discs have different transverse profile contours, repeating periodically along the rotor axis, and each disc is offset at an angle with respect to the rotor. two adjacent disks of the same rotor in such a way that the three disks have a common control curve through the section and form a chamber.

The synchronizing device is preferably arranged to provide the same direction of rotation of the 1: 1 gear rotors.

Preferably, the two discs adjacent to the disc having a surface area whose sectional angle is greater than the sectional angle of the core surface have surface areas whose sectional angles are smaller than the sectional angle of the core surfaces.

The intermediate surfaces of the disc, respectively, form with the intermediate surface of the adjacent disc a continuous intermediate surface with a common control curve.

The rotors are preferably mounted with parallel axes, said control curves being cylindrical control curves, wherein the thickness of the sections decreases in the direction of the pressure side.

The rotor axes are preferably arranged as oblique axes, wherein said control curves are conical control curves, and the diameters of the rotor sections decrease in the direction of the pressure side, wherein the sections of the outer rotor and the inner rotor have the shape of a spherical cup instead of a disc shape.

Thus, the above objects have been achieved in a rotary piston machine of the above type in which the section angles of the surface area and the core surface of the respective disc are not identical, the discs having different transverse profile contours that periodically repeat along the piston shaft, each disc being offset at a certain angle with respect to two adjacent disks of the same rotary piston in such a way that the three disks have common control curves through one section of their core surfaces and form a chamber.

With this type of construction, a graded helical pitch with horizontal intermediate sections between the two chambers is formed on a separate unassembled rotary piston. The sequence of chambers is formed in an axial direction with optionally variable volume, i.e. with optionally variable internal compression through optionally variable thickness on the disk-shaped sections.

The use of sequences of disc-shaped sections with different transverse profile contours means that for a certain number of chambers, the total number of sections can be kept lower than in the case of rotary piston machines equipped with progressively tapered pistons known in the art.

With fewer sections, each rotary piston can be manufactured in one piece, which contributes to a significant improvement in dimensional stability, and which presents less thermal risk than a single disk assembly.

If the operating temperature of the rotary piston machine is low as a result of the method used, the rotary pistons can also be formed from a sequence of individual profile disks arranged in the axial direction one on top of the other, thereby saving production costs.

In the following description, the term "disc" or "disc", unless otherwise specified, is used both for individual profile discs and for the disk sections of a one-piece piston.

The machine according to the invention is contactless and constantly rotating. Spaces between two rotary pistons that rotate with each other can be divided into three types:

-4GB 304588 B6

(a) Surface area / core area of opposing disc-shaped sections: These linear gaps are determined by the accuracy of the production of the cylindrical surfaces of the pistons, and the distance between the two axes of rotation. Low gap values can be achieved using conventional manufacturing technology.

b) The front surface / front surface of the disk sections lying on top of each other: the gap widths of these flat gaps can also be kept low using modern production and machine tools. The large gap lengths along the flow direction between the rotary pistons ensure a good seal and thus a good end vacuum.

c) Intermediate / Area / Intermediate Area of Opposite Sections, In particular Peaks / Concave Flank: By offsetting the disc-like sections of the present invention, these gap widths are not critical and may be in the millimeter range, substantially facilitating the manufacture and machining of the intermediate surfaces. Since these gap widths also define the permissible angular clearance between the rotary pistons, the permissible angular clearance is very large, which means that the requirements for the synchronization device of the rotary piston machine are lower, so that their selection or implementation is easier.

The theoretical cycloid curved intermediate surfaces, i.e. parallelepipedal surfaces, which respectively connect the surfaces and the core surfaces, i.e. the outer and core cylinders of the disk-shaped section have no critical sealing function when rotating the rotary pistons in the opposite direction, so they describe the theoretical maximum contour.

The profile contour of the intermediate surface can be made somewhat smaller or flatter than the theoretical maximum contour and can be made much easier, for example a contour without a cut-out and / or truly straightforward, so it can be very advantageous for these reasons and very efficient in operation . As a result, the permissible angular clearance during operation also increases.

For practical reasons, the two discs adjacent to the disc with an outer surface whose section angle is greater than the section angle of the core surface have outer surfaces whose section angles are smaller than the section angles of the core surfaces.

Thus, for practical reasons, there is also a large difference between the section angles of the outer surface area and the core surface of the disk-like section. The section angle of this surface area for a disk with a small outer surface area is preferably less than 90 °, and more preferably less than 60 °. Such a disc is opposite the disc of another rotary piston with a section angle of the outer surface which is correspondingly greater than 270 ° or greater than 300 °.

The chambers of the respective rotary piston are preferably arranged in such a way that the intermediate surfaces of the disc form, with the intermediate surface of the adjacent disc, respectively, a continuous intermediate surface with common control curves.

The synchronization device of the rotary piston machine according to the invention can be chosen in such a way that the two off-axis rotary pistons have the opposite direction of rotation. The outer dimensions of the rotary pistons, the diameters of the core cylinders, as well as the gearing can then be selected in such a way that the pistons roll with respect to each other without slipping, with the surface area of the disc section rolling over the core surface of the opposite section.

If the number of surfaces and core surfaces of the disc-shaped section is correspondingly the same as that of the opposite section of the other rotary piston, then a 1: 1 ratio must be selected. However, if this number varies, then the appropriate conversion must be selected.

In other embodiments with asymmetric energy distribution, the two off-axis rotary pistons have the same direction of rotation.

In yet other compact embodiments, the two rotary pistons have an inner axis, i.e., they are formed as an outer rotor and an inner rotor with an additional G-shaped rotor.

-5GB 304588 B6

In several rotary piston designs, the disk-like sections of the respective rotary piston have only two alternating front sectional contours.

In addition, the diameters of the surface or outer cylinders and core cylinders of the off-axis rotary pistons may be correspondingly identical, wherein the first piston section has one front sectional profile contour, while the opposite second piston section has another front sectional profile contour in the same plane below the right angles to the piston axis.

The two rotary pistons can also be designed as a main rotor and a secondary rotor with different diameters and, consequently, with variable shaft outputs up to 100: 0%, which is advantageous for the synchronization device.

In some such rotary piston embodiments, sequences of sections with different front cutout profile contours alternate with circular locking disks so that the respective piston has sections with three or more different profile contours.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail by way of examples of specific embodiments thereof, the description of which will be given with reference to the accompanying drawings, in which:

Fig. 1 is a side elevational view of a first embodiment of a rotary piston according to the present invention with fourteen non-superimposed disks numbered from 0 to 13;

Fig. 2 is a side elevational view of a corresponding second rotary piston according to a first embodiment of the present invention;

Fig. 3 is a plan view from the suction side of the assembled rotary piston of Figs. 1 and 2, with the "0" section of the rotary piston of Fig. 2 being omitted;

Fig. 4 shows a section / flow, i.e. a rotation angle diagram, which schematically illustrates the operation of the first embodiment;

Fig. 5 is a side elevational view of a pair of eleven-section rotary pistons according to a third embodiment of the present invention with a main rotor of eleven sections, numbered from 0 to 10;

Fig. 6 is a cross-sectional view of section 1 of the assembled rotary piston of Fig. 5;

Fig. 7 is a cross-sectional view of section 2 of Fig. 5;

Fig. 8 is a section / angle diagram that schematically illustrates the operation of a third embodiment of the present invention;

Fig. 9 is a section / angle diagram illustrating schematically the operation of a fourth embodiment of the present invention;

FIG. 10 is a section / angle diagram showing schematically the operation of a fifth embodiment of the present invention;

Fig. 11 is a side elevational view of a pair of rotary pistons according to a sixth embodiment of the present invention with seventeen sections numbered from 0 to 16;

Fig. 12 is a cross-sectional view of a section 1 assembled by the rotary pistons of Fig. 11;

Fig. 13 is a cross-sectional view of a section 2 of the assembled rotary pistons of Fig. 11;

Fig. 14 is a cross-sectional view of a section 3 of the assembled rotary pistons of Fig. 11;

Fig. 15 is a cross-sectional view of a section 4 of the assembled rotary pistons of Fig. 11;

FIG. 16 is a section / flow, i.e., a rotation angle diagram, which schematically illustrates the operation of a sixth embodiment of the present invention;

Fig. 17 is a section / flow diagram that schematically illustrates the first nine sections of the seventh embodiment and their interaction;

Fig. 18 is a cross-sectional view of an outer rotor section 1 of the embodiment of Fig. 17;

Fig. 19 is a cross-sectional view of an outer rotor section 2 of the embodiment of Fig. 17;

Fig. 20 is a cross-sectional view of an internal rotor section 1 of the embodiment of Fig. 17;

Fig. 21 is a cross-sectional view of an internal rotor section 2 of the embodiment of Fig. 17;

Fig. 22 is a cross-sectional view of a G-shaped sickle rotor in the embodiment of Fig. 17; and Fig. 23 is a partial axial sectional view of a portion of the inner rotor and portions of the outer rotor surrounding it, in an eighth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

1 to 4, the rotary pistons are mounted off-axis and parallel axes in a housing (not shown), provided with two cylindrical bores and an external synchronizing device.

The rotary pistons have the opposite direction of rotation. The rotary pistons have fourteen disk-shaped sections, in particular two media entry and exit sections 0 and 13 and profile sections 1 to 12 with two different alternating profile contours, each section having an outer surface area M1 with a small section angle alternating respectively. with a section having a surface area M1 with a large section angle.

In the exemplary embodiment shown, these section angles have respective values of somewhat less than 36 ° and somewhat less than 144 ° so that the angular clearance remains intact.

Figures 3 and 4 show the successively rotated angular position of one section relative to the next, i.e. 72 ° from one section to the same one, the intermediate surface z of the section being arranged correspondingly above, respectively below, at viewed in the axial direction with respect to the intermediate surface of an adjacent section of another profile contour.

In this way, a chamber is enclosed, respectively (see FIG. 2), with portions of the core surfaces ki 'and KT and intermediate surfaces of the T adjacent sections, thereby creating a sequence of axial chambers of varying volume, internal compression being achieved by varying realization of internal compression, the axial expansion of the sections and thus of the chambers gradually decreases from input to output.

-7EN 304588 B6

The clearance volumes formed between the rotary pistons have small consequences, and the large gap depth between the rotary pistons creates a very good end vacuum.

As shown in the figures of Figures 1 to 4, there are three types of spacing between rotary pistons:

(a) cylinder / cylinder;

(b) transverse surface / transverse surface;

c) peaks / concave flank.

The latter type of gap determines the respective angular clearance and is not critical, that is, it may lie in the millimeter range, opening up a wide range of possibilities for realizing the synchronization device. With the rotary pistons of this embodiment, a compression ratio of 1: 4 is achieved, resulting in significant savings in energy consumption and heat development. The total number of profile sections is therefore minimized by the specific number of chambers and compression.

In the embodiment shown in FIG. 1, the sections I and 2 have the same thickness. From section 2 to section 3, the thickness decreases by a factor of approximately 1.4, while the thicknesses of sections 3 and 4 are the same, etc.

With this section thickness distribution, where the two successive and opposite sections of one and the other rotary piston have the same thickness, the energy distribution decreases to about 50:50% for each rotary piston. The thickness of the sections may also decrease from each section to the next depending on the selectable and geometric rule.

In a second embodiment, not shown separately in the drawings, the disk-like sections of the two rotary pistons have the same cross-sectional profile contours and the same displacement angles as shown in Figures 3 and 4.

The difference from the first embodiment lies in the distribution of the thickness of the sections. The sections 1, 3, 7, etc. are thick sections whose thickness gradually decreases from the strongest section 1 to the last section on the pressure side.

The sections 0, 2, 4, 6 etc. are all weak discs. With this type of construction, one rotary piston assumes the role of the main rotor, while the other rotary piston assumes the role of the secondary rotor. The energy distribution between the main and secondary rotor can be displaced to approximately 85:15%.

5 to 15 are mounted off-axis and parallel axes in two cylindrical openings in the housing (not shown) with an external synchronizer. They are unbalanced with widely varying shaft power of up to 100%. The minimum number of different profile contours of the piston sections depends on the arrangement of the profile sequences.

In the third embodiment, which is shown in Figures 5, 6, 7 and 8, the projections of the main rotor and the secondary rotor differ greatly.

As can be seen in the figures of Figures 6 to 8, the main rotor has two alternating and different profile contours, one profile contour having an outer surface area m 3 with a small section angle, and alternating with a profile contour whose outer surface the surface M3 has a large section angle. The same alternation (m3 ', M3') occurs at the secondary rotor.

As shown in the embodiment of FIG. 5, the main rotor has eleven disk sections. This main rotor has five thick sections I, 3, 5, 7 and 9, the thickness of which gradually decreases towards the pressure side, and whose outer surface area of m3 has

-8EN 304588 B6 Small section angle. These five sections form pumping sections P1 to P5. These are separated and surrounded by six sections 0, 2, 4, 6, 8 and 10 having only a short angular core cutout k3, each forming a control section S that transports the gas to the next pumping section.

For example, the thickness of the five pumping sections into the pumping section P1 to the pumping section P5 may be reduced from approximately 70, respectively, by one third to a thickness of 13 mm, with each control section S having a thickness of 10 mm. The total length of the main rotor is then approximately 240 mm.

An exemplary embodiment is shown schematically in Figure 8, wherein the core diameter of the main rotor is the same as the outer diameter of the secondary rotor. In a 1: 1 ratio, the rotors roll together, one by one. Under these conditions, the energy distribution between the main rotor and the auxiliary rotor is approximately 75: 25%.

In the fourth exemplary embodiment shown in FIG. 9, the diameters of the main rotor and the secondary rotor also vary greatly. The main rotor also has two different alternating profile contours in cross section, similar to the third exemplary embodiment.

However, the secondary rotor has three different profile contours, in particular in the following order:

- a sectional section i consisting of a single core disc,

- profile section 2 in the form of an outer cylinder with a low-angle cut-out,

a profile section 3, which again consists of a core disc, and

a profile section 4, which consists of a solid outer cylindrical disk and forms a locking disk.

Indeed, in this arrangement of the main rotor and the secondary rotor, 100% of the energy is supplied to the main rotor, with 0% of the energy being supplied to the secondary rotor.

FIG. 10 schematically illustrates a fifth embodiment of the present invention.

The main rotor has two different alternating transverse profiles, each having two identical outer surfaces and two identical core surfaces, which are opposed to each other.

The relative dimensions of the sectional angles of the surface area and the core surface vary from section to section, as in the previous embodiments. The secondary rotor respectively has only one outer surface and one core surface with alternating large and small angles.

The synchronization device is designed in such a way that the speed of rotation of the secondary rotor is twice the speed of rotation of the main rotor. With this design, a highly asymmetric energy distribution can be achieved, in particular about 85% for the main rotor and about 15% for the secondary rotor.

The five exemplary embodiments described above have a number of advantages:

- with a low number of sections, the rotary piston can be manufactured as a monoblock, which substantially improves dimensional stability during operation;

the large gap lengths between the rotary pistons along the flow provide a good seal and thus a good end vacuum;

- the large permissible play facilitates production and assembly, as well as the use of the synchronization mechanism.

-9EN 304588 B6

In the third, fourth and fifth embodiments, the intermediate surfaces of the rotor are formed without a cut-out, thereby simplifying the number of operations during manufacture.

In asymmetric embodiments, the energy fraction of the drive rotary piston and the driven rotary piston vary considerably, which also provides an advantage in selecting and performing the synchronization device.

In rotary pistons made up of individual profile discs, the number of different individual components is reduced by using identical control and locking discs.

A sixth embodiment of the present invention, the pair of rotary pistons of which is shown in Figures 11 to 15, is a non-contact, parallel-axis, biaxial, off-axis, continuously rotating transfer machine with a housing with two cylindrical bores and an external synchronizer. wherein the two rotary pistons have the same direction of rotation.

Rotary pistons, whose diameters vary greatly, are designed as the main rotor and the secondary rotor. Both the main rotor and the secondary rotor have at least three different types of profile.

In the exemplary embodiment shown in Figures 12 to 15, both the main rotor and the auxiliary rotor have four different types of profile that create a sequence of different pairs of disc-shaped sections, in particular

- an initial section (see Fig. 12) in which the main rotor has a large angle surface (M6); the segmental angle of the core may be kept very low or, as shown in FIG. 12, may even be omitted, so that the outer surface of this section is only interrupted by an asymmetrical sickle-shaped cut-out. This section serves as an initial control disk S, being positioned opposite the initial section of the auxiliary rotor, which simply consists of a core cylindrical disk;

- the second section P of the main rotor (see Fig. 13) has a core surface (K6) whose section angle is greater than 180 °, an extremely short outer surface (m6) and two longitudinally extended intermediate surfaces (z6). Opposed there is a second section of the secondary rotor with an outer surface area (M6 ') whose section angle is greater than 180 °, with a minimum core surface (k6') which, as can be seen in FIG. or almost completely disappear by continuous fusion of the two intermediate surfaces (z 6 ') along the tangent to the core cylinder. This section creates the actual pumping stage of the sequence;

- the third section of the main rotor (see FIG. 14) is identical in shape to the first section, but is arranged symmetrically in the plane as can be seen in the figures of FIGS. 12 and 14. a core cylindrical disk;

- the fourth section (see FIG. 15) of the main rotor is formed by a single core disk, serving as a channel K for the compressible medium. Opposite this is the fourth section of the auxiliary rotor with an uninterrupted outer surface which serves as a locking disk.

FIG. 11 shows a complete construction of an exemplary embodiment with seventeen disk sections, in particular two end disks (E) 0 and 16;

with three complete S-P-S-K sequences of the four sections 1 to 4, 5 to 8, 9 to 12 just described; and with an incomplete sequence S - P - S, i.e. an initial control disc 13, a pumping stage 14 and a second control disc 15.

-10GB 304588 B6

The control discs S of the main rotor can all be formed from thin discs, since they serve only to pass the medium from the pump stage P to the next channel K and again to the next pump stage.

Gradation of the axial extension of the pump stages and the channel stages may be subject to various mathematical rules determined by their function.

Table 1 shows, by way of example, two gradations in which the thickness of the thickest stage, in particular of the pump stage 1, has been arbitrarily set to 1.

Table 1

Example 1 Example 2 Pl 1 1 Kl 0.8 0.5 P2 0.6 0.64 K2 0, 46 0.32 P3 0, 36 0.42 K3 0.29 0.21 P4 0.21 0.28

As can be seen in Example 1, the thickness of the stages gradually decreases in the order P1, K1, P2, K2, etc., with the thickness of both the pump stages and the channel stages decreasing, but alternating in their thickness, in Example 2. For a P1 thickness of, for example, 49 mm, and a control disk thickness of 8 mm in the gradation of Example 2, the resulting main rotor length is approximately 240 nm.

The operation of this sixth embodiment results from the schematic representation of FIG. 16.

As a result, the sequence of axial chambers is realized in an off-axis transfer machine whose pistons rotate in the same direction. The piston shaft outputs vary considerably, meaning that the energy distribution is extremely asymmetric, up to 100: 0%.

This embodiment has the following advantages:

- contours without cut-outs allow extremely simple production; in particular, the production of the monoblock can be very easily carried out;

- a large permissible play is advantageous for both production and assembly;

- large gap lengths along the flow allow good end vacuum to be achieved;

- the same direction of rotation and the large permissible play open further possibilities for the synchronization device; in view of the low power of the slave rotor, toothed belts can even be used.

In the sixth embodiment described above, the two rotary pistons are generally cylindrical with parallel axes of rotation. The control curves whose surface forms the surfaces, the core surfaces and the intermediate surfaces of the disk-shaped sections are cylindrical control curves, the generating lines being parallel to the axes of rotation.

-11 GB 304588 B6

It will be appreciated by those skilled in the art that when using cross-sectional contours and angular misalignment of the piston sections of the present invention, the rotary piston may also be conical, wherein the control curves whose course defines the peripheral surfaces of the disks are cone control curves, the circumference of the discs is conical and their diameters gradually decrease in the direction towards the pressure side. The axes of rotation of the two pistons are then not parallel but intersect.

In these embodiments, the diameter changes produce internal compression. Diameter changes can be used in addition to disc thickness changes or instead of disc thickness changes.

Figures 17 to 22 show a seventh embodiment, in particular a non-contacting, continuously rotating, displacement machine with parallel axes, two axes and an inner axis.

The machine has a hollow outer rotor, an inner rotor, and a G-shaped sickle rotor positioned between the outer and inner rotors. The rotors have the same direction of rotation as shown in FIG. 17.

The outer rotor (A) and the inner rotor (I) have a plurality of disk-like sections which mesh with each other in pairs, their thickness decreasing towards the pressure side, each disk having at least one surface area and one core surface formed by the control surfaces curves running along the arcs of circles centered on the axis of the respective rotor and connected respectively by an intermediate surface (z7) or (z7 ').

As shown in Figures 17 to 22, the discs for the outer and inner rotors have two repeating profile contours that repeat periodically along the piston axis, alternately in this embodiment. The section angles of the surface area and the core surface (m7, k7) or (m7, K7), (m7 ', K7') and (M7 ', k7') of the respective disc are not identical, each disc being offset relative to two adjacent discs of the same rotor in such a way that the three disks have a common control curve through one section of their core surfaces and intermediate surfaces and form a chamber).

In this embodiment, a sequence of axial chambers is formed in a machine with an internal axis. A 1: 1 synchronization device is used. The synchronizing device may be arranged inside the outer rotor. Therefore, a simple non-lubricating coupling mechanism can be utilized. This embodiment makes it possible to achieve a very compact construction with good heat dissipation, which has the same advantages as the above-described off-axis embodiments.

The eighth embodiment also includes a two-axis, internal-axis, non-contact, constant-rotation, positive displacement machine provided with an outer rotor, an inner rotor, and a G-shaped sickle rotor positioned between the outer rotor and the inner rotor. The rotors have the same direction of rotation. A 1: 1 transmission is used. Unlike the seventh embodiment, the two axes of rotation are arranged as oblique axes so that the diameters of the rotors vary along the tapered path.

The outer rotor and the inner rotor have a plurality of sections which engage each other in pairs, and which, unlike the seventh embodiment described above, are designed not as cylindrical discs with planar transverse surfaces but as curved sections, in particular as spherical cup sections.

In the transverse section, the profile contours of the two successive outer and inner rotor sections are similar to those shown in Figures 18 to 22. This means that a sequence of axial chambers is realized in a machine with an inner axis and an inclined axis. rotoiy rotate with 1: 1 ratio.

The gaps between the front faces of the two sections that are offset one after another are the gaps between the two spherical faces (Ku, Ku '), as shown in Figure 23.

- 12GB 304588 B6

The large gap lengths along the flow direction provide good sealing in this embodiment as well as good end vacuum.

Internal compression occurs by varying the rotor diameter, which can be increased or decreased by additional thickness variations in the profile sections, and locally modulated if necessary, depending on the use of the positive displacement or vacuum pump.

This design is very compact with only a small number of components and good heat dissipation. The synchronization device can be designed as a simple non-lubricating coupling mechanism, for example as a universal connection within a positive displacement machine or vacuum pump.

Claims (16)

A machine with rotary pistons for compressible media, with at least two rotary pistons sealed in a common housing and rotatable relative to each other in a controlled manner, the two rotary pistons having a plurality of disc sections (1, 2, 3, ...), which engage with each other in pairs whose thickness and / or diameter decrease in the direction of the pressure side, each disk-like section having at least one outer surface area (ml, M1) and one core surface (k1, k1) formed by control curves running along the arcs of the circles centered on the axis of the respective rotary piston, and respectively interconnected by an intermediate surface (zl, zT), characterized in that the section angles of the outer surface and the core surface of the respective disk section are not equal, the disk sections having different transverse profile sections contours, repeating periodically p along the axis of the piston, each disk-shaped section being offset by an angle with respect to two adjacent disk-shaped sections of the same piston, the three disk-shaped sections having a common control curve through one section of their core surfaces and forming a chamber. Rotary piston machine according to claim 1, characterized in that the two adjacent disk sections of the disk section with an outer surface area whose section angle is greater than the section angle of the core surface have surface areas whose section angles are less than segment angles of core surfaces. Rotary piston machine according to claim 2, characterized in that the intermediate surfaces of the disk-shaped section form, with the intermediate surface of the adjacent disk-shaped section, a continuous intermediate surface with a common control curve. Rotary piston machine according to one of Claims 1 to 3, characterized in that the two rotary pistons are mounted off-axis and parallel axes, the disk-shaped sections having outer surfaces and inner core surfaces which are formed by respective control curves of one outer cylinder. and one core cylinder, wherein the thickness of the disk-shaped sections decreases towards the pressure side. Rotary piston machine according to claim 4, characterized in that the respective diameters of the outer surfaces and the core surfaces of the two rotary pistons are identical. Rotary piston machine according to claim 5, characterized in that the section angle of the outer surface area of each second disk portion of the rotary piston is less than 90 °, in particular less than 60 °. - 13GB 304588 B6 Rotary piston machine according to claim 6, characterized in that the thickness of the disk-shaped sections in the direction towards the pressure side decreases by a constant factor for every two disk-shaped sections. A rotary piston machine according to claim 4, characterized in that the rotary pistons have different outer diameters, wherein the thickness of the main rotor sections having an outer surface area with a small section angle is greater than the thickness of the main rotor sections with surface areas. large section angle. A rotary piston machine according to claim 8, wherein the diameter of the core surface of the main rotor is equal to the diameter of the external surface area of the secondary rotor. 10. The rotary piston machine of claim 8, wherein each disk portion of the main rotor has two opposing core surfaces and two outer opposing surface surfaces. Rotary piston machine according to one of Claims 8 to 10, characterized in that the sequence of periodically repeating transverse profile contours comprises disc sections consisting of a core cylinder only and / or blocking disc sections. Rotary piston machine according to claim 1, characterized in that it comprises rotary pistons mounted on an inner axis, in particular an outer rotor, an inner rotor, and a G-shaped rotor, the outer rotor and the inner rotor having a plurality of disk sections, with each other engaging in pairs the thickness and / or diameter of which decreases in the direction of the pressure side, each disk-shaped portion of the outer and inner rotor having at least one outer surface and a core surface formed by control curves extending along the arcs of the centerline of the respective rotor, and respectively interconnected through the intermediate surface, wherein the angles of the outer surface and the core surface of the respective disk-shaped section are not identical, the disk-shaped sections having different transverse profile contours, repeating periodically along the and each of the disk-shaped sections is offset by an angle with respect to two adjacent disk-shaped sections of the same rotor, the three disk-shaped sections having a common control curve through the section and forming a chamber. Rotary piston machine according to claim 12, characterized in that the two adjacent disk sections of the disk section with an outer surface area whose section angle is greater than the section angle of the core surface have surface areas whose section angles are smaller than the section angle angle of core surfaces. Rotary piston machine according to claim 13, characterized in that the outer intermediate surfaces of the disk-like section form, with the intermediate surface of the adjacent disk-like section, a continuous intermediate surface with a common control curve. Rotary piston machine according to one of Claims 8 to 14, characterized in that the rotors are supported with parallel axes, the control curves being cylindrical control curves, the thickness of the sections decreasing in the direction towards the pressure side. Rotary piston machine according to one of Claims 12 to 14, characterized in that the rotor axes are arranged as oblique axes, wherein the control curves are conical control curves, and the diameters of the rotor sections decrease in the direction of the pressure side, wherein the outer section sections The rotor and the inner rotor have the shape of a spherical dish instead of a disc shape.